elasticsearch – python Elastic search BadRequestError while making insensitive match analyzer

I’m trying to build an index that is searchable for a possible case insensitive exact match. The Elasticsearch version is 8.6.2 with Lucene version is 9.4.2. The code is run in Python with Python’s elasticsearch library.

settings = {"settings": {
    "analysis": {
      "analyzer": {"lower_analizer": {"tokenizer": "whitespace", "filter": [ "lowercase" ]} }
    }
  }
}

mappings = {"properties": {
                "title": {"type": "text", "analyzer": "standard"},
                "article": {"type": "text", "analyzer": "lower_analizer"},
                "sentence_id": {"type": "integer"},
    }
}

I copied the settings from Elasticsearch’s tutorial. However, it returned the following error:

BadRequestError: BadRequestError(400, 'illegal_argument_exception', 
'unknown setting [index.settings.analysis.analyzer.lower_analizer.filter]
 please check that any required plugins are installed, or check the
 breaking changes documentation for removed settings')

I’m not sure where to proceed, as it implies lowercase function does not exist?